Tool-dressing mechanism



Jan. 31, 1928. Y 1,657,832

' H. E. KEMPTON ET AL TOOL DRESSING MECHANISI' Filed May 25. 1924 s Sheets-Sheet 1 Jan. 31, 1928. 1,657,832

H; E. KEMPTON ET AL TOOL DRESSING MECHAIIISM Filed May 23. 1924 s Sheets-Sheet 2 Q3 a umna!!! I w/mm Jan. 31, 1928, 1,657,832

H. E. KEMPTON ET AL TOOL DRESSING MECHANISM Filed May 23. 1924 3 Sheets-Sheet 3 Patented Jan. 31, 1928.

UNITED STATES 1,657,832 PATENT OFFICE.

' HERBERT E, KEMPTON AND KEITH I. GALLIMORE, OF FOND DU LAC, WISCONSIN, AS-

SIGNORS, BY MESNE ASSIGNMENTS, TO THE HEALID MACHINE COMPANY, 01' WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

-l-'.COL-DRESSING MECHANISM.

Application filed May 23,

Our invention relates toan improved truing device for grinding machines, and has particular reference to means for dressing the grinding wheel automatically during the machine operation.

The primary object of our invention is to provide an improved automatic dressing device which after being initially positioned will repeatedly dress the grinding element incidentally through the normal machine operations, thereby increasing quantity production, lessening the duties of the attendant, and assuring an infallible and precise dressing at regular intervals.

Another object of the invention is to provide a device of the above character which is sturdy and simple in construction, thereby ensuring rigidity and consequently accurate and uniform dressing; in which the parts are 20 interchangeable; and which is capable of precise adjustment over a wide range to adapt it for a. large variety of work.

A further object is to provide a fixed dressingdevice which can be adjusted for taper 25 grinding as well as straight grinding, and which after its initial adjustment need not be changed and need not be moved out of the way during certain times in the machine operation.

Another object is to provide a dressing tool which can be angularly and rotatably adjusted to present new edges to the grinding wheel, thereby increasing its life and efiiciency.

Further objects and advantages will become apparent as the. description proceeds.

In the accompanying drawings, Figure 1 is a fragmentary plan view partially in section of a grinding machine to which a 40 dressing device embodying the features of our invention has been attached.

Fig. 2 is an end view of the same.

Fig. 3 is a side view of the dressing device.

Fi 4 is a sectional detail view of the dressing tool holder taken in the plane of line 4-4 of Fig. 3.

Figure 5 is a fragmentary, longitudinal, vertical cross-sectional view through the ma- 60 chine, the chuck being removed to show the supporting bracket for the dressing tool more fully.

While our invention is susceptible of various modifications and alternative construc- 1924. Serial No. 715,359.

tions, we have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that we do not thereby intend to limit the invention to the precise construction shown but aim in the appended claims to cover all legitimate modifications and alternative constructions falling within the spirit and scope of the invention. v

Referring to the drawings, 'represents a chuck having a plurality of suitable jaws 11 for supporting a work blank 12, and 13 designates a grinding element adapted to operate on the blank. While our invention is susceptible of use with many other types of grinding machines, we have herein shown it as applied to a machine adapted to grind the internal bores of work blanks. The grinding element 13 is adapted to be automatically moved from a relatively remote position into the bore of the work blank 12 to grind the latter, and then withdrawn again into its inoperative position by any suitable and well known means (not shown). The chuck 10 is mounted on a rotatable spindle 14 journaled in a headstock casing 15, and adapted to be driven by a pulley 16 deriving power from any suitable source. The headstock casing is supported by a cross feed slide 17 mounted on, the machine base 18, and is rotatably adjustable thereon about a vertical axis. A worm 19 mounted in a bracket 20 on the slide 17 and meshing with a gear segment21 on the casing 15 provides a means for effecting an arcuate adustment of the casing 15, and bolts 22 serve to lock the same in adjusted position. The slide 17 may be fed transversely of the base 18 to bring the blank 12 into engagement with the grinding element 13 by a rotatable feed screw 23 having a threaded engagement with a nut 24 on the under side of said slide. The construction thus far described is old and well known, and forms no part of the present invention.

The dressing mechanism comprises amain horizontal supporting bracket 25 which is formed with a pair of parallel spaced arms 26, and secured to the headstock casing 15 for rotation therewith by a pair of curved upstanding flanges 27 integral with said arms and held rigidly in place by bolts 28. The arms 26 are connected by a central rib 29 and a horizontalweb 3O underlying the chuck 10 and adapted to catch any falling material, such as work blanks or grindings. A pair of longitudinal flanges 31 formed on the adjacent sides of the arms 26 extend inwardly toward each other and are each provided with a plurality of alined adjusting holes 32. The flanges 31 are bridged by a transverse base member 33 which is adapted to be adjusted longitudinally of the arms 26. Studs 34 extending selectively and upwardly through certain of the holes 32 into tapped bores 35 in the ends of the member 33 serve to lock the latter in adjusted position. Preferably the base member 33 is formed like an inverted channel with a plurality of alined bores 36 tapped through the back.

Mounted on the base member 33 for adjustment longitudinallythereof is an upstanding bracket 37 which is secured in position by studs 39 extending through lateral ears 40 into selective engagement with the bores 36. The ears 40 are provided with elongated slots 41 which allow a fine adjust ment of the bracket 37 laterally of the base member 33. The bracket can thus be accurately positioned at any desired point along the arms 26 after it has been approximately positioned by moving the member 33 along the flanges 31.

Formed on the bracket 37 is a sleeve 42 which is closed at one end. and extends transversely of the arms 26. Referring now to Fig. 4, the stem 43 ofatool holder is slidably mounted in the open end of the sleeve 42, and is held against rotation by a pin 44 engaging a longitudinal slot 45 in its surface. Threaded into a tapped bore 46 in the inner end of the stem 43 is an adjusting screw 47 which extends outwardly through the closed end of the sleeve 42 and may be rotated by a knob 48. A collar 49 on the screw 47 serves to hold the latter in position. The stem 43 may be locked in adjusted position by a nut 50 threaded through a tubular projection 51 on the sleeve 42.

The tool holder is provided with a bifurcated head 52. Mounted for angular adjn'stment in a horizontal plane between the forks of the head 52 is a mounting 53 supporting a diamond or any other suitable cutting member 54 at its outer end. The mounting 53 in the present instance is secured in a diametrical bore 55 of a cylindrical block 56 rotatably mounted in the head 52, and may be removablv clamped in place by a nut 57 threaded into the upper end of the block. A threaded stem 58 on the lower end of the block 56 extends through the lower fork of the head 52 and carries a tightening nut 59 whereby the diamond 54 may be held in any angular adjusted position. The supporting parts are so constructed and arranged that the diamond 54 can be angularly, rotatably and longitudinally adjusted. By reason of these adjustments, new surfaces of the diamond as the latter wears away can be presented to the wheel being dressed, thereby providing new cutting edges and increasing the life and efiiciency of the diamond.

The operation of the device is as follows: The base 33, bracket 37 and head 52 are properly adjusted to position the diamond point 54 just ahead of the chuck 10, and in line with the inner periphery of the work blank 12. The grinding element 13 is now moved freely past the point 54 into the bore of the work blank 12 which is then fed toward the element until ground to the proper size, and it is then withdrawn. On its outward movement the element 13 is automatically dressed by the diamond 54 which has been advanced with the work blank 12. Thus the grinding element 13 in effect moves through a rectangular cycle with respect to the diamond 54, and is automatically dressed after each operation. Since the amount of stock to be removed is small and some wear on the grinding wheel has resulted, only a small amount of abrasive is removed to obtain the new cutting surface. lVhere taper work is to be ground, angular adjustment of the point 54 may be necessary.

It will be seen that we have provided a simple and efiicient automatic dressing device which performs its function incidentally through the normal operation of the grinding machine parts. By virtue of coarse and fine adjustments laterally and longitudinally of the machine, the device can be precisely positioned at any desired point. The device after its initial adjustment puts the necessary dressing of the operating element beyond the concern of the o erator. and therefore insures regular and requent dressing. Due to the rigidity of the device, the dressing is invariable and accurate.

When the headstock 15 is angularly moved to grind conical bores in workpieces, the supporting bracket 25 moves with it, and thus only minor adjustments of the position of the diamond 54 are necessitated. The absence of this feature in prior devices of this class has placed a limitation on the adaptability of the dressing device to use in connection with all types of workpieces, since a wide angular adjustment of the headstock of a grinding machine results in a large horizontal displacement of the chuck, and if the dressing tool did not move, such displacement might very well place the cutting line at the completion of the grinding operation beyond the range of adjustability of the said dressing tool.

We claim as our invention:

1. dressing mechanism for a grinding machine of the type having a base a grinding element, and a headstock adapted to support a work blank, said element and headstock being mounted for relative lateral movement comprising, irr combination, a support secured to said headstock, a bracket adjustably mounted on said support directly ahead of said blank; and a cutting tool supported by said bracket and positioned su stantially in alinement with the surface of said blank and in a horizontal plane throu h the axis of said element, said tool after t e cross feed serving to dress said grinding element as the latter is withdrawn to an inoperative position. 5

2. A dressing mechanism for a grinding machine of the type in which a reciprocatory grinding element is mounted to move into and out of a chuck on a support revolvably adjustable about a perpendicular axis and having a relative cross feed, comprising, in

' combination, a support ri id with respect to positioned to dress the surface of the support for said chuc and mounted for movement therewith, a bracket adjustably mounted on said last mentioned sup ort directly ahead of said chuck, and a cutting tool adjustably supported by said bracket and positioned substantially in. alinement with the surface of work to be ground, said tool being adapted to dress said element as the latter passes by. r

3. A dressing mechanism for grinding machines of the type having a base, a cross feed slide on said base, a rotatable headstock on said slide, said headstock supporting a work chuck, and a grinding element mounted for movement into and out of said chuck, comprising, in combination, a bracket rigidly mounted on said headstock, and a dressing tool mounted on said bracket, said tool being I said le-' ment as the latter is withdrawn from said chuck after the com letion of the cross feed. 4. A dressing mechanism for grinding machines of the type comprising a work chuck and a. grinding element having a relative transverse feed comprising, in combination, a bracket stationary relative to said chuck and having a air of spaced arms underlying said grin-ding element, a base member spanning said arms and adjustable therelong,-a

bracket adjustablysupported by said base I member, and a cuttin tool adjustably mounted on said last mentioned bracket, said cutting tool being positioned to dress the surface of said grinding element as the latter is moved longitudinally of said chuck.

5. A dressing mechanism for machines of the type comprisin a support, a work holding chuck mounte on said support and a grinding element comprising, in combination, a bracket secured to said support, said machines of the type in which the chuck is mounted for adjustment about a vertical axis and has a relative cross feed with respect to a reciprocatory grinding element comprising an angularly ad ustable dressing tool mounted for movement with said chuck and adapted to engage the grinding element as the latter is moved byin one direction.

7. A dressing device for a machine of the type in which a work chuck is rotatably mounted in a headstock angularly adjustable about a vertical axis and has a relative cross feed with respect to a reciprocatory grinding element comprising, in combination, a bracket rigidly mounted on said headstock for angular adjustment therewith, an an 'ularly adjustable dressing tool adjustably mounted on said bracket and positioned to engage the grinding element as the latter is moved past to dress said wheel parallel to the finished surface of the work.

In testimony whereof we have hereunto affixed our signatures.

- HERBERT E. KEMPTON. KEITH F. .GALL'IMORE. 

